The prior art to which the present invention is directed includes a wide variety of cooling water equipment that has a purification function for the purpose of purifying and cooling water in a water tank, such as is mainly used for breeding fish. One such prior art device previously developed by the present inventor is disclosed by the Japanese Document TOKU-KAI-HEI No. 11-318271.
However, it has been found that prior art cooling water equipment having a purification function, such as disclosed in the afore-mentioned TOKU-KAI-HEI No. 11-318271, have had some practical problems such as: (1) limitations due to a relatively low purification capability, which makes it difficult to make such equipment small in size and energy efficient, (2) difficulties in disbursing the purification load uniformly on a filter's surface in order to use water treatment filters efficiently, and (3) limitations due to loud noise caused by the water purification equipment.
To solve the problems mentioned above, the present inventor has also developed cooling water equipment T (hereinafter called a “filtration-function-equipped cooling water equipment”) wherein the filtration function of the equipment is augmented, as illustrated in FIG. 7, by incorporating oxygen-supply-capable cooling water equipment U, such as illustrated in FIG. 6 and disclosed in TOKU-GAN No. 2001-110564, and a filtration equipment F.
Namely, the prior art system is constructed so that oxygen-supply-capable cooling water equipment U illustrated in FIG. 6 is equipped with a water conduction pipe 2, a dispersion body 3, a dripping water guide body 4, a guide plate 4a, dripping water guide pipe 4b, a filler 5, an air supply device 6, a silencing and filtration material 7, and the like, in a treatment tank body 1. The prior art system operates such that water W to be treated drips onto the filler 5 through the dripping water guide pipe 4b, then after biological treatment inside of filler 5 the biologically treated water W1 is filtrated by the silencing and filtration material 7 while a counter-current air flow is made to run into the filler 5 in a counter-current manner through an air passage part P. In this case, the oxygen-supply-capable cooling water equipment U also includes a treated water discharge mouth 8, an air inlet 9, an air exhaust port 10, a cap body 11, and filtrated, biologically treated water W3.
FIG. 7 illustrates filtration-function-equipped cooling water equipment T of the prior art, wherein water purification and filtration functions of the oxygen-supply-capable cooling water equipment U are further augmented. Equipment T is so designed that filtered and biologically treated water W3 is guided from the oxygen-supply-capable cooling water equipment U to the separately installed filtration equipment F. After an additional filtration treatment has been performed by filter 13, the water W4 is then returned to the water tank 12. In this case, the filtration-function-equipped cooling water equipment T also includes a supporter base 14, a pump 15, coupling pipes 16 and 17, and a water level WL.
Oxygen-supply-capable cooling water equipment U, constructed in accordance with the afore-mentioned document TOKU-GAN No. 2001-110564, and a filtration-function-equipped cooling water equipment T incorporating equipment U, have the following advantages: (a) a high water purification performance per volume unit, (b) the ability to make equipment that is smaller in size and energy efficient, and (c) also allowing a low noise of operation. However, certain problems still remain to be solved with respect to the prior art equipment U and T.
First, there is a problem with splashes of water W to be treated. More particularly, with operation of the oxygen-supply-capable cooling water equipment U, as evident from FIGS. 6 and 7, dripping water from pipes 4b mixes in the air flow A and is exhausted through an air exhaust port 10 and is splashed outside of tank body 1 together with the air flow A. For structural reasons, it is difficult to perfectly prevent the dripping water from splashing as described above.
To avoid the occurrence of splashing, a splash prevention cover, and the like, could be mounted on the outside of the air exhaust port 10. However, this added splash prevention cover will cause other problems concerning the appearance of the equipment and the amount of space the equipment will require. Furthermore, with cooling water equipment T wherein the filtration function is augmented as shown in FIG. 7, the method of fitting such equipment to a water circulating system is a matter of concern. In other words, it is feared that the appearance of the equipment, which becomes important when keeping aquarium fish, would be impaired due to the reason that the water tank 12, the filtration equipment F and the oxygen-supply-capable cooling water equipment U are mounted together, one on top of the other thereby forming a 3-step shape.
In addition, with cooling water equipment T wherein the filtration function is augmented as shown in FIG. 7, it is feared that when replacing the filter 13 of the filtration equipment F an activation of microbes is seriously effected, which possibly will require a long time for the aquarium environment to recover from the activation of microbes.